what is staining

Staining is a technique used to enhance contrast in samples, generally at the microscopic level. It is used to highlight biological specimens at the microscopic level to study them at higher magnification for histopathological studies and diagnostic purposes. Staining can also be used to study the structure of crystalline polymers. There are two types of staining: in vivo staining and in vitro staining. In vivo staining is the process of dyeing living tissues, while in vitro staining involves coloring cells or structures that have been removed from their biological context. Certain stains are often combined to reveal more details and features than a single stain alone. Scientists use different mounting techniques, combined with dyes and microbiology stains to add contrast to specimens and make them easier to observe at a microscopic level and aid with identification. Stains are selected based on the type of sample being observed and what organisms or cells need to be observed. Most commonly, a positive stain is used as the stain is readily absorbed by the cell or organism making it stand out against the background. Differential staining involves the use of multiple stains to make different organisms different colors and therefore distinguishable from each other.